15 November 2019

How Do You Weigh A Living Whale?

Credits to Fredrik-Christiansen (Photo from Oceanographic Magazine)

The obvious answer is that scientists can't really use a scale.

For starters, dead whales can weigh as much as 210 kg to a whopping 160 t. Besides, measurements can be inaccurate given the physical distortion of carcasses caused by bloating and deflation.

But scientists have something new in their arsenal.

Something that can be used above the sea...

But first, let’s learn about how whales are weighed in the past.

The only way to get data on the body mass of whales was to weigh dead or stranded individuals. Studying blue whales, for instance, was limited to dead specimens from whaling operations, fisheries bycatch and beach strandings.

This can be especially limiting with scientists boxed from collecting longitudinal data over a whale's lifespan. This has prevented the inclusion of body mass in many studies in ecology, physiology and bioenergetics.

But now scientists can accurately estimate the weight of free-living whales.

The answer? 


Scientists took aerial photos of 86 southern right whales off the coast of Península Valdés, Argentina.

The waters were clear and the sheer number of whales gathering every winter to breed allowed for the measurement of both the dorsal and lateral sides of the whales.

With crisp images, they were able to get data for length, width and height.

These values were then plugged into a model (and voila!) an accurate calculation of whales' body volume and mass.

What's more fascinating is that the parameters of the model can be adjusted to estimate as well the size of other marine mammals, an alternative that can be considered over invasive methods.

This discovery opens a lot of doors for research.

For one, they can now explore the growth of known aged individuals to calculate their body mass increase over time and the energy requirement for growth. They can also peek into the daily energy requirements of whales and derive prey consumption.

Weight data can also provide insights on how chronic stressors influence whale survival and how they can produce offspring.

This innovation also paved the way to recreating a 3D mesh of the whale and a full-color 3D model in the works, which can be used for studying movement and for educational purposes.

SeaLifeBase hosts data on the weight of marine mammals, from blue whale to the dwarf sperm whale, the smallest known whale.

Feel free to explore.

Happy learning!

26 July 2019

A rare and unforgettable sight: The rainbow-colored blanket octopus

What's better than seeing a rare sea creature? 

Well, seeing two of them and capturing them on camera, of course!

The deep sea never fails to amaze us with bouts of often odd and elusive, yet all the more wonderful creatures.

Take the recent sighting of the rare blanket octopus, which the lucky cameraman Joseph Elayani was able to encounter and film in the wild. On a night dive in the open sea at Romblon (Philippines), at depths of 9-22 m [1], he caught sight of not only one but a pair of female rainbow-colored blanket octopus. It was a glorious moment for Elayani as he witnessed the rapidly shifting colors of the arms, from hues of pastel blues and purple to stunning reds and oranges. This change in color is deemed to be the octopus' reaction from the different light levels of the camera or as a strategy to ward off predators [2].

Credits to Joseph Elayani via Cater News

Blanket octopuses are pelagic creatures found in the Atlantic, Mediterranean and the Pacific, in tropical to subtropical waters. They belong to the genus Tremoctopus [3]. It got its name from the sheets of webbing that extend between some of their arms [4]. 

Octopus, in general, are known to be masters of disguise, changing color patters to blend to their environment and escape predators or sneak on their prey or even mimic other species. Blanket octopus, meanwhile, are known to spread their majestic arms out to drive away would-be predators [4].

One of the things that make them odd is the sheer size difference between sexes: while males are less than an inch long, females can grow up to six feet long and weigh up to 40,000 more than males. It's also unusual that they are immune to the stinging cells of the perilous jellyfish Portuguese man-of-war, which it uses as a weapon against predators [4]. 

Current population data on blanket octopus is unknown [4]. For the meantime, immerse in the beauty that these two lovely octopuses have to offer.

We welcome collaboration with marine scientists and enthusiasts alike. If you have more information or photos on blanket octopuses, you can leave us a message at sealifebase[at]gmail[dot]com.

[1] Good News Pilipinas. Rare rainbow-colored blanket octopus caught on diver’s camera in Romblon waters. Retrieved from https://bit.ly/2Y3HEVL

[2] Best, S. (18 Jun 2019). Stunning rainbow blanket octopuses spotted swimming in depths of ocean. Mirror Retrieved from https://bit.ly/2YiRpKU

[3] Turgeon, D.D.; Quinn, J.F. Jr.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.; Rosenberg, G.; Roth, B. (1998). Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks, 2nd ed. American Fisheries Society (Special publication 26), Bethesda, Maryland. 526 p.

[4] National Geographic. Blanket octopus. Retrieved from https://on.natgeo.com/32VuskK

[5] USA Today (4 June 2019). Rare 'rainbow' blanket octopuses caught on camera in the Phillippines | USA TODAY. Retrieved from https://bit.ly/2L92yem

22 May 2019

The role of biodiversity in human health

The United Nations has marked May 22 as The International Day for Biological Diversity to raise awareness and understanding of biodiversity issues. 

This year's theme, "Our Biodiversity, Our Food, Our Health," focuses on the invaluable role of biological diversity in human health and well-being. We can show our appreciation for the resources nature provides us every day by truly understanding (or simply reminding ourselves) where we get our resources for good health—the food we eat, the water we drink, and the air we breatheBy doing so, we are putting first the species and the ecosystems that keep our health in check and make our lives worthwhile. 

We can be a catalyst of change in small ways, be it by buying local food or using recyclable bags.

Here in SeaLifeBase, we celebrate marine biodiversity, from foraminiferans to cetaceans, from which we depend a lot for our health and well-being. If you're keen to learn more, visit us here.

29 April 2019

Q-quatics welcomes its new researchers!

Two new fresh graduates, Selina De Leon and Fayte Sicnawa, jump on board the Q-quatics team last April 1. They have since been involved in the identification of fishes in partnership with the University of Western Australia and the carry forward of global fisheries catch reconstructions led by the Sea Around Us.

Selina De Leon, a BS Biology graduate, hails from the University of the Philippines Diliman. She took up courses on marine sciences, ichthyology, ecology, biodiversity, and conservation. Selina’s fascination for the ocean started when she saw the iconic BBC documentary series Blue Planet. That made her want to study marine life and experience it up close. Last Aril 2018, she volunteered for the humpback whale research expedition (Balyena.org) in Camiguin Island, Calayan, Cagayan.

Fayte Sicnawa, a member of the Indigenous People of Kalinga, studied BS Biology major in Wildlife Biology at the University of the Philippines Los Baños. Upon graduation, she went on to teach Chemistry, Biology and Environmental Science at Trace College for a year. As a wildlife biologist, she’s aware of the decline in the sheer biodiversity of species in the country. She therefore feels strongly about the need for their conservation. She believes that the training she'll get in Q-quatics would leverage this passion. Today, she’s pursuing a master’s degree in Wildlife Biology.

Welcome aboard,  Selena and Fayte!

20 March 2019

Creature feature: Meet the dumbo octopus

Illustration by Maxeen Bayer based on the Disney character Dumbo

Deep in the ocean floor lives an octopus, its common name derived from the Disney character Dumbo who can fly with its big ears. Just as the sky is for the endearing elephant, the dumbo octopus hails from the deep, steering the waters by flapping its ear-like fins [1].

To date, there are 21 known species of dumbo octopus (Grimpoteuthis) [2]. Being bathypelagic animals, they live 13,000 feet below water (or almost 4000 m) and are rarely seen in shallow waters. They live in tropical to temperate latitudes and have been observed in New Zealand, California, Oregon, Philippines, and in other areas [3].

Dumbo octopus comes in different sizes, shapes, and colors. Its average size is 20 to 30 cm (7.9 to 12 inches) in length and its mantle, either U- or V-shaped. Like other families of octopi, their tentacles are umbrella-shaped, characterized by webbing between their tentacles, which help them navigate while swimming and crawling on the surface. Their ear-like lateral fins also help them propel around the water [4].

Grimpoteuthis has large eyes, about a third the diameter of their head, but it has limited use in the eternal darkness of the deep oceans. However, to defend itself against predators, it uses its ability to change color and camouflage against the ocean floor. When it camouflages, the ears emit a different color than the rest of its body [4].

They are carnivorous, eating isopods, amphipods, bristle worms and more. Their mouth is different from their kin, engulfing their prey rather than grinding and ripping [1].

The male octopus has a special protuberance in one of its 8 tentacles used to deliver the sperm to a female octopus, which the octopus stores until conditions are favorable for laying eggs on shells or small rocks on the seafloor. Young dumbo octopi are large when they are born and must survive on their own. They can live for 3 to 5 years [1].

Very little is known about these creatures. If you have more information on dumbo octopus, SeaLifeBase welcomes collaboration. Kindly send us a message at sealifebase(at)q-quatics(dot)org.

Written by Maxeen Danielle Bayer

[1] Helmenstine, A.M. (2018, April 24). All about Grimpoteuthis, the dumbo octopus. ThoughtCo. Retrieved from https://bit.ly/2W3CUtP
[2] WoRMS Editorial Board (2019). World Register of Marine Species. Available from http://www.marinespecies.org at VLIZ. Accessed 2019-03-15. doi.10.14284/170
[3] Oceana. Cephalopods, crustaceans and other shellfish: dumbo octopus. Retrieved from https://bit.ly/2Jfo2qM
[4] Ocean Conservancy (2018, October 8). Everything you need to know about the dumbo octopus. Retrieved from https://bit.ly/2OAYNBg
[5] National Geographic (2018, October 29). Rare dumbo octopus shows off for deep-sea submersible. YouTube. Retrieved from https://bit.ly/2u9gcEP